Mechanism for fixing probe card

ABSTRACT

In a mechanism for fixing a probe card, the probe card and a support frame are joined to each other about the axis of each of the probe card and the support frame by a plurality of first fastening members. Also, the outer circumferential edge portion of the support frame is fixed by a plurality of second fastening members to a holder fixed to a probe unit. The probe card is held by the mechanism such that the central region of the probe card is restricted by the first fastening members and the outer circumferential portion of the probe card is not restricted so as to be rendered free. It follows that the probe card is expanded toward the outer circumferential edge portion by thermal expansion under a high-temperature. However, the probe card is prevented from being deformed in the shape of a dome.

CROSS-REFERENCE TO RELATED APPLICATIONS

Notice: More than one reissue application has been filed for the reissueof U.S. Pat. No. 6,831,455. The reissue applications are applicationSer. No. 11/638,658 (the present application) and application Ser. No.11/956,758, filed Dec. 14, 2007 (which is a continuation reissueapplication of the present application).

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. 2002-319253, filed Nov. 1,2002; and No. 2003-158533, filed Jun. 3, 2003, the entire contents ofboth of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a probe unit for examining theelectrical characteristics of a target object, particularly, to a fixingmechanism of a probe card for fixing a probe card arranged within a bodyof a probe unit, i.e., a fixing mechanism of a probe card, which permitssuppressing the thermal deformation of the probe card during examinationunder high-temperature.

2. Description of the Related Art

In the manufacturing process of a semiconductor device, used is anexamining apparatus, e.g., a probe unit as shown in FIG. 1, which iscalled a prober, for examining the electrical characteristics of aplurality of devices formed on a wafer. The probe unit shown in FIG. 1comprises a loader chamber 1 for receiving wafers W therein and equippedwith a mechanism for transferring the wafers W, and a probe chamber 2for examining the electrical characteristics of the wafer W transferredfrom the loader chamber 1. Each of the wafer W is pre-aligned in thetransfer process of the wafer W in the loader chamber 1, and theelectrical characteristic of the wafer W is examined in the probechamber 2.

In the prober chamber 2, the pre-aligned wafer W is disposed on a mainchuck 3 provided with a heating source for heating the wafer W andmaintaining the wafer at a predetermined temperature. The main chuck 3is arranged on an XY table 4 that permits the wafer W to be moved in theX-direction and the Y-direction, and wafer W is disposed on a prescribedposition by driving the XY table 4.

A probe card 5 provided with a plurality of probe pins 5A is arrangedabove the main chuck 3, and the probe card 5 is supported by an aligningmechanism 6. The aligning mechanism 6 is operated so as to permit theprobe pins 5A to be positioned accurately above a plurality of electrodepads of the wafer W held by the main chuck 3. Also, a lift mechanism isarranged inside the main chuck 3. During the examining process, thewafer W is moved upward by the lift mechanism so as to allow the probepins 5A to be brought into a mechanical and electrical contact with theelectrode pads. Also, after the examining process, the wafer W is moveddownward by the lift mechanism so as to cause the probe pins 5A to beseparated mechanically and electrically from the electrode pads.

Also, a test head T of a tester is rotatably arranged on a head plate 7defining the probe chamber 2, as shown in FIG. 1. The test head T iselectrically connected to the probe card 5 via a performance board (notshown). The temperature of the wafer W disposed on the main chuck 3 isset at a prescribed temperature falling with a prescribed temperaturerange, e.g., a temperature range of between −40° C. and +150° C., andthe temperature of the wafer W is maintained at the set temperatureduring the test. Also, during the test, a signal for the examination istransmitted from the tester to reach the probe pins 5A via the test headT and the performance board noted above, with the result that the signalfor the examination is applied from the probe pins 5A to the electrodepads of the wafer W so as to examine the electrical characteristics of aplurality of semiconductor devices formed on the wafer W. Where thewafer W is set at a high-temperature not lower than the roomtemperature, the wafer W is heated to the prescribed temperature via atemperature control mechanism including the heating source provided inthe main chuck 3 and, then, the electrical characteristics of the waferare examined.

The circuit of the chip formed on the wafer W has been rendered ultrafine in recent years and the diameter of the wafer W itself has beenmuch enlarged in recent years. In accordance with these tendencies, thediameter of the probe card 5 has been also enlarged in recent years. Inaccordance with the enlargement of the diameter, the probe card 5 isreinforced by a support frame 5B made of a metallic material such asstainless steel as shown in FIGS. 2A and 2B so as to impart asufficiently rigid structure to the probe card 5. The probe card 5 isfixed to the head plate 7 by an annular holder 8 together with thesupport frame 5B. To be more specific, the probe card 5 is fastened andfixed to the holder 8 together with the support frame 5B by a pluralityof fastening members 9A such as a screw. Also, the holder 8 is fastenedand fixed to the head plate 7 via a plurality of fastening members 9B.

In the mechanism for fixing the probe card described above, a problem isgenerated in the case of examining the electrical characteristics of thewafer W in the initial stage of the heating under a high-temperatureenvironment, e.g., a high-temperature environment of 100° C. To be morespecific, the lower side of the probe card 5 or the holder 8 is moreheated than the upper side by the heat radiated from the main chuck 3.As a result, the lower side is thermally expanded more greatly than theupper side, with the result that the probe card 5 or the holder 8 isbent. What should also be noted is that the probe card 5 is fixed to theinner circumferential edge portion of the holder 8. As a result, theprobe card 5 is prevented from being elongated radially outward and iselongated radially inward so as to be bent downward, as shown in FIG.2A. It should also be noted that the outer circumferential edge portionof the holder 8 is fixed to the head plate 7. As a result, the holder 8is elongated radially inward so as to cause the probe card 5 to befurther bent downward. Such being the situation, the probe pins 5A aredisplaced vertically downward so as to cause the probe pressures betweenthe probe pins 5A and the electrode pads of the wafer W to be setgreater than the preset values. As a result, the electrode pads and theunderlayers thereof are bruised so as to invite a defective examination.Particularly, where the probe card 5 is reinforced by the support frame5B as shown in FIGS. 2A and 2B, a serious problem is generated that theprobe card 5 is much affected by the thermal expansion of the supportframe 5B.

It should also be noted that, in the examination stage under ahigh-temperature, the probe card 5 and the support frame 5B aresufficiently heated so as to be thermally expanded, as shown in FIG. 2B.Also, since the holder 8 is sufficiently heated so as to be thermallyexpanded, an outward stress is exerted from the probe card 5 and thesupport frame 5B to the fastening member 9A. At the same time, an inwardstress is exerted from the holder 8 to the fastening member 9A. Wheresuch a function is generated, the probe card 5 is bent upward as shownin FIG. 2B, which is opposite to that shown in FIG. 2A. In this case,the probe pins 5A are moved upward so as to bring about possibly adefective contact. The phenomenon shown in FIGS. 2A and 2B is similarlygenerated in the case where the probe card 5 is reinforced by thesupport frame 5B.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a mechanism for fixingthe probe card, which permits suppressing the stress generated by thethermal deformation of the probe card so as to suppress the displacementof the probe pins in the up-down direction, thereby improving thereliability of the examination of the electrical characteristics of thewafer.

According to an aspect of the present invention, there is provided afixing mechanism arranged within a probe unit for examining theelectrical characteristics of a target object, the target object beingmaintained under a high-temperature environment within a probe chamber,comprising:

-   -   a probe card provided with a plurality of probes which are to be        brought into an electrical and mechanical contact with the        target object, which is configured to examine the electrical        characteristics of the target object, the probe card being        exposed to a high-temperature atmosphere;    -   a support frame configured to support the probe card in the        central portion thereof;    -   a plurality of first fastening members configured to fasten the        probe card on the support frame to fix the probe card;    -   a holding frame configured to hold the probe card and the        support frame in the outer peripheral portions thereof so as to        permit the probe card to be thermally expanded toward the        periphery thereof, the holding frame being fixed to the probe        unit; and    -   a plurality of second fastening members configured to fasten the        holding frame on the support frame to fix the holding frame.

Additional objects and advantages of the present invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the present invention.The objects and advantages of the present invention may be realized andobtained by means of the instrumentalities and combinations particularlypointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentinvention, and together with the general description given above and thedetailed description of the preferred embodiments given below, serve toexplain the principles of the present invention.

FIG. 1 is a front view, partly broken away, schematically showing theconfiguration of a probe unit provided with a conventional mechanism forfixing the probe card;

FIGS. 2A and 2B are cross-sectional views schematically showing in amagnified fashion the state of the probe card shown in FIG. 1 in theexamining stage under a high-temperature;

FIG. 3 is a cross-sectional view schematically showing the mechanism forfixing the probe card according to one embodiment of the presentinvention;

FIG. 4 is a plan view schematically exemplifying the configuration ofthe support frame shown in FIG. 1;

FIG. 5 is a cross-sectional view schematically showing the configurationof the mechanism for fixing the probe card according to anotherembodiment of the present invention;

FIG. 6 is a plan view schematically showing the configuration the bottomsurface of the mechanism shown in FIG. 5;

FIG. 7 is an oblique view showing the configuration of a modification ofthe probe card shown in FIG. 3; and

FIG. 8 is a cross-sectional view schematically showing the configurationof the mechanism for fixing the probe card according to still anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments of the present invention in respect of the mechanismfor fixing the probe card will now be described with reference to theaccompanying drawings.

FIG. 3 schematically shows the configuration of a fixing mechanism 10according to one embodiment of the present invention. As shown in FIG.3, a disk-like probe card 11 is fixed to the fixing mechanism 10. Thefixing mechanism 10 comprises a support frame 12 for supporting theprobe card 11 from the upper surface and an annular holder 13 forholding the outer peripheral edge portions of the probe card 11 and thesupport frame 12. The fixing mechanism 10 is fixed to a head probe 14arranged within a probe chamber having a configuration similar to theconventional configuration. As a result, the fixing mechanism 10 permitsthe probe card 11 to be fixed to and held by the head plate 14. Theprobe unit comprising the probe chamber has substantially the samestructure as that of the conventional probe unit and, thus, thedescription thereof is omitted. For example, the fixing mechanism 10 ofthe probe card according to this embodiment of the present invention canbe applied to the probe unit described previously in conjunction withthe prior art with reference to FIG. 1 and, thus, attention should bepaid to the description of the prior art. It should also be noted thatthe probe fixing mechanism of the present invention can be appliedapparently to not only the probe unit shown in FIG. 1 but also the probeunit having the other known configuration.

A main chuck 15 is arranged within the prober chamber. The wafer W heldstationary on the main chuck 15 can be transferred in the horizontaldirection (X, Y-directions) by an XY table and the up-down direction(Z-direction) by an up-down mechanism (i.e. Z-transfer mechanism)provided in the main chuck 15.

The probe card 11 comprises a plurality of probe pins 11A, a contactorsection 11B having the probe pins 11A mounted thereto, and a circuitsubstrate 11C having the contactor section 11B fixed to the centralportion thereof. The contactor section 11B, the circuit substrate 11Cand the support frame 12 are joined to each other via a plurality offirst fastening members 16A formed of screws, etc., with the result thatthe probe card 11 and the support frame 12 are formed integral. To bemore specific, the plural first fastening members 16A are arranged insymmetry with respect to the axis of the circuit substrate 11C so as topermit the probe card 11 to be fastened to the central region of thecircuit substrate 11C with a uniform fastening force.

As described above, the fixing mechanism shown in FIG. 1 is constructedsuch that the probe card 11 is integrally joined to the central portionsof the support frame 12 and the circuit substrate 11C. It follows that,in the fixing mechanism shown in FIG. 3, the elongation in the centralportion of the circuit substrate 11C caused by the thermal expansion ismuch suppressed even if the circuit substrate 11C is thermally expandedby the heat released from the main chuck in the examining stage under ahigh-temperature. As a result, the upward or downward dome-like thermaldeformation along the axis of the circuit substrate 11C is suppressed soas to prevent the probe pins 11A from being displaced upward ordownward.

As shown in FIG. 3, the support frame 12 is in the form of a disk havinga diameter larger than that of the circuit substrate 11C and is arrangedsuch that the center of the support frame 12 substantially coincideswith the center of the probe card 11. Alternatively, the support frame12 is in the form of a wheel including an outer circumferential circularrim 12A and spokes extending from the circular rim to the hub in thecentral portion of the wheel, as shown in FIG. 4.

The outer circumferential rim 12A of the support frame 12 protrudes inan amount corresponding to the thickness of the circuit substrate 11C soas to permit the circuit substrate 11C to be held between the rim 12Aand the holder 13, and the support frame 12 is formed such that thetotal thickness of the support frame 12 is substantially equal to thesum of the thickness in the inside portion of the support frame 12 andthe thickness of the circuit substrate 11C. Also, the inner diameter ofthe rim 12A is made larger than the outer diameter of the circuitsubstrate 11C so as to have a clearance δ formed between the insidesurface of the rim 12A and the outer circumferential surface of thecircuit substrate 11C. Naturally, the difference between the innerdiameter of the rim 12A and the outer diameter of the circuit substrate11C corresponds to the clearance δ. It should be noted in thisconnection that, even if the circuit substrate 11C is thermally expandedfrom the center toward the outer circumferential surface, the thermalexpansion of the circuit substrate 11C is absorbed within the clearanceδ so as to prevent the outer edge of the circuit substrate 11C fromabutting against the inside surface of the rim 12A. Also, the supportframe 12 permits the probe card 11 to be fixed to the holder 13.

The holder 13 has an annular configuration such that the cross sectionthereof is L-shaped and comprises an annular outer peripheral edgeportion 13A and a flange-like inner peripheral edge portion 13B steppeddown from the outer circumferential edge portion 13A and formed within aplane differing from the plane on which the outer circumferential edgeportion 13A is formed. The outer diameter of the holder 13 is madelarger than the diameter of the central hole of the head plate 14, andthe inner diameter of the holder 13 is made smaller than the outerdiameter of the circuit substrate 11C included in the probe card 11.

The head plate 14 is formed on the prober chamber such that the mainchuck 15 is capable of movement during the examination under ahigh-temperature within a range in which the main chuck 15 does notreach the region right under the head plate 14. Because of thisparticular configuration, the thermal effect given by the heat releasedfrom the main chuck 15 to the head plate 14 can be diminished as much aspossible.

Also, the outer peripheral edge portion 12A of the support frame 12 ismounted on the inner peripheral edge portion 13B of the holder 13, andthe outer peripheral edge portion 12A is fixed to the inner peripheraledge portion 13B by a plurality of second fastening members 16B. Itfollows that the outer peripheral edge portion of the circuit substrate11C included in the probe card 11 is supported by the inner peripheraledge portion 13B of the holder 13 and the support frame 12. It should benoted, however, that the outer peripheral edge portion of the circuitsubstrate 11C is not restricted by, for example, the fastening membersand is allowed to be elongated in the radial direction by the thermalexpansion. Such being the situation, the circuit substrate 11C can befreely elongated or shrunk within the clearance δ even if the circuitsubstrate 11C is thermally expanded during the examination under ahigh-temperature. On the other hand, the holder 13 is fastened and fixedto a stepped edge portion 14A on the inner circumferential region of thehead plate 14 by a plurality of third fastening members 16C which areequidistantly arranged in the circumferential direction of the outerperipheral edge portion 13A. The head plate 14 comprises an outer frame14B having an L-shaped cross section and a stepped edge portion 14Aextending inward from the outer frame 14B. The central hole defined bythe stepped edge portion 14A is recessed relative to the outer frame14B, and the central hole noted above is formed within the recess. Itfollows that the peripheral edge portion 14A of the central hole has areference plane set in a lower portion relative to the outer frame ofthe head plate 14.

Incidentally, each of the second and third fastening members 16B and 16Cis formed of, for example, a screw.

The circuit substrate 11C of the probe card 11 is formed as amulti-layered wiring structure by a known material such as a glass epoxyresin. Also, each of the support frame 12 and the holder 13 is formed ofan inorganic material having a low thermal expansion coefficient such asa ceramic material like aluminum nitride or a metallic material having alow thermal expansion coefficient such as a nickel alloy like Invar. Itis desirable for these materials to have a thermal expansion coefficientfalling within a range of between zero and 3×10⁻⁶, and more desirably tohave a small thermal expansion coefficient not greater than 1×10⁻⁶.Where the support frame 12 and the holder 13 are formed of thesematerials, it is possible to lower the thermal expansion generated inthe support frame 12 and the holder 13 by the heat released from themain chuck 15 to 1/10 of less of that generated in the conventionalstructure.

The examination of the electrical characteristics of the wafer W under ahigh-temperature by using the probe unit described above will now bedescribed. If the wafer W is disposed on the main chuck 15 under thestate that the main chuck 15 is heated to a prescribed temperature,e.g., to 150° C., the wafer W is heated to a prescribed temperature bythe main chuck 15. Also, the wafer W is aligned with the probe pins 11Aby the aligning mechanism including the main chuck 15 and the XY stage.Then, an index transfer of the wafer W in which the wafer W istransferred stepwise by a width corresponding to the chip formed on thewafer W is performed in accordance with movement of the main chuck 15.It follows that the electrode pad of the chip formed on the wafer W isaligned to face the probe pins 11A. If the electrode pad is aligned withthe probe pins 11A, the wafer W is moved upward via the main chuck 15 soas to bring the electrode pad of the wafer W into contact with the probepins 11A. Further, if the wafer W is overdriven within an allowablerange in which damage is not done to the wafer W so as to bring theelectrode pad of the wafer W into a sufficient contact with the probepins 11A, the electrode pad is brought into an electrical contact withthe probe pins 11A without fail.

If a signal for the examination is supplied from the tester to the probecard 11 under this state, the signal for the examination is applied fromthe probe pins 11A to the wafer W so as to start the examination of theelectrical characteristics of the chip formed on the wafer W. The signalfrom the chip is supplied through the probe pins 11A to the tester sideas a signal indicating the result of the examination. The signalsupplied to the tester side is analyzed and stored in a memory device(not shown), thereby finishing the examination of a prescribed deviceunder a high-temperature. Then, the main chuck 15 is moved downward soas to release the contact between the electrode pad and the probe pins11A. Further, the index transfer of the wafer W and the verticalmovement of the wafer W are repeated for examining the electricalcharacteristics of another chip so as to finish the examination of thewafer W under a high-temperature.

In performing the examination under a high-temperature, the temperatureof each of the probe card 11, the support frame 12 and the holder 13 iselevated by the heat released from the main chuck 15. It should be notedthat the probe card 11 is fixed in its central portion to the supportframe 12 by the plural first fastening members 16A. As a result, thecentral portion of the probe card 11 fastened by the plural fasteningmembers 16A, 16A is prevented from being displaced in the verticaldirection. Also, the outer circumferential edge portion of the probecard 11 is not fixed and is rendered free. Therefore, even if the probecard 11 is thermally expanded toward the outer circumferential edgeportion, it is possible to suppress the displacement of the probe pins11A in the vertical direction. It should also be noted that the mainchuck 15 is movable during the examination under a high-temperaturewithin a range in which the main chuck 15 is not moved to reach a regionright under the head plate 14. It follows that it is possible tosuppress the thermal effect generated by the heat released from the mainchuck 15 and given to the head plate 14. Further, each of the supportframe 12 and the holder 13 is formed of a material having a low thermalexpansion coefficient. Therefore, even if the temperature of each of thesupport frame 11 and the holder 13 is elevated by the heat released fromthe main chuck 15, it is possible to suppress the elongation of thesupport frame 11 and the holder 13 caused by the thermal expansion,leading to the capability of controlling satisfactorily the displacementof the probe pins 11A in the vertical direction.

As described above, according to this embodiment of the presentinvention, the probe card 11 and the support frame 12 are fastened toeach other by a plurality of first fastening members 16A in the vicinityof the axis of each of the probe card 11 and the support frame 12. Also,the outer circumferential edge portion 12A of the support frame 12 isfastened and fixed to the holder 13 by a plurality of second fasteningmembers 16B such that the outer circumferential edge portion of theprobe card 11 is not fixed and is rendered free. It follows that it ispossible to suppress satisfactorily the thermal deformation in thevertical direction of the probe card 11 and the displacement of theprobe pins 11A in the vertical direction during the examination under ahigh-temperature. Such being the situation, it is possible to preventthe damage done to the electrode pad and to the underlying layer so asto make it possible to carry out the examination under ahigh-temperature satisfactorily.

Also, according to this embodiment of the present invention, the outercircumferential edge portion of the probe card 11 is positioned betweenthe support frame 12 and the holder 13, and a clearance δ is formed onthe outside of the outer circumferential edge surface of the probe card11. It follows that the probe card 11, i.e., the circuit substrate 11Cincluded in the probe card 11, is elongated by the thermal expansionwithin a range of the clearance δ and, thus, the stress does not act onthe circuit substrate 11C so as to make it possible to suppress furtherthe displacement of the probe card 11 in the vertical direction.

A mechanism for fixing the probe card according to another embodiment ofthe present invention will now be described with reference to FIGS. 5and 6. Specifically, FIG. 5 is a partial cross-sectional viewschematically showing the configuration of the mechanism for fixing theprobe card according to another embodiment of the present invention, andFIG. 6 is a partial plan view schematically showing the configuration ofthe bottom surface of the mechanism shown in FIG. 5. Incidentally, thoseportions of the mechanism shown in FIGS. 5 and 6, which are equal to orwhich correspond to the portions of the mechanism shown in FIG. 3 aredenoted by the reference numerals used in FIG. 3 so as to omit theoverlapping description.

In the fixing mechanism 10 of the probe card shown in FIGS. 5 and 6, aheat-insulating sheet 17 is formed on the lower surfaces of the holder13 and the head plate 14, as shown in FIG. 5. The mechanism shown inFIGS. 5 and 6 is substantially same configuration as that of themechanism shown in FIG. 3, except that the heat-insulating sheet 17 isformed in the mechanism shown in FIGS. 5 and 6. The heat-insulatingsheet 17 is covered with a heat resistant plate 18, and the plate 18 isfixed to the holder 13 and the head plate 14 by a fastening member 19such as a screw. As shown in FIG. 6, the plate 18 is formed in a fanshape, and the fan-shaped plate 18 is arranged over the entire region ofthe holder 13 and the head plate 14. It is desirable for a clearance forabsorbing the thermal expansion of the plate 18 to be formed between theadjacent sections of the plate 18. The material of the heat-insulatingsheet 17 is not particularly limited, though it is desirable for theheat-insulating sheet 17 to be formed of a material that is unlikely togenerate dust. To be more specific, it is desirable for theheat-insulating sheet 17 to be formed of, for example, a siliconesponge. It is possible to suppress the temperature elevation of theholder 13 and the head plate 14 by forming the heat-insulating sheet 17on the lower surfaces of the holder 13 and the head plate 14, with theresult that it is possible to further suppress the bending of the probecard 11 in the vertical direction.

It is also possible to form a heat-insulating sheet (not shown) on thelower surface of the probe card 11 or between the probe card 11 and thesupport frame 12 so as to suppress the temperature elevation of each ofthe probe card 11 and the support frame 12. By taking such a measure, itis possible to suppress the thermal expansion of the probe card 11 andthe support frame 12, thereby further suppressing the bending of theprobe card 11, i.e., the displacement of the probe pins 11A in thevertical direction, so as to realize the examination under ahigh-temperature with a further improved reliability.

It is possible for the card holder 13 that is shaped as shown in FIG. 7to be incorporated in the mechanism shown in FIG. 3 or 5. To be morespecific, FIG. 7 shows the outer shape of the probe card 13 directedtoward the side of the probe chamber. As shown in FIG. 7, the cardholder 13 comprises an annular outer circumferential edge portion 13Aand a flange-like inner circumferential edge portion 13B stepped fromthe outer circumferential edge portion 13A toward the side of the probechamber and extending toward the center of the card holder 13. Aplurality of slits 20 are radially formed in the flange-like innercircumferential edge portion 13B. These slits 20 are formedsubstantially in symmetry with respect to the center of the holder 13.Also, recesses 21 are formed to extend from the inner edge of the innercircumferential edge portion 13B toward the outer circumferential edgeportion 13A. The recesses 21 are radially arranged substantially insymmetry with respect to the center of the holder 13 like the slits 20and extend to reach a region positioned between the adjacent slits 20.It follows that the slits 20 and the recesses 21 are alternatelyarranged in the inner circumferential region of the innercircumferential edge portion 13B.

In the apparatus in which the card holder 13 of the particularconfiguration is incorporated in the mechanism, the card holder 13 thatis exposed to a high-temperature during the examination under ahigh-temperature receives heat radiation so as to be thermally expanded.However, the thermal expansion of the card holder 13 is absorbed by theslits 20 and the recesses 21, with the result that the card holder 13itself is thermally expanded in the shape of a dome. It follows that itis possible to prevent the probe card 11 from being displaced in amanner to be pushed out toward or pulled into the probe chamber.Particularly, since the recesses 21 are formed to extend to reach aregion between the adjacent slits 20, the card holder 13 is preventedfrom being deformed such that the inner circumferential region of thecard holder 13 is corrugated even if the card holder 13 is thermallyexpanded.

FIG. 8 is a cross-sectional view schematically showing the configurationof a mechanism 10 for fixing the probe card according to still anotherembodiment of the present invention.

The fixing mechanism 10 of the probe card shown in FIG. 8 hassubstantially the same configuration as that of the fixing mechanismshown in FIG. 3, except that the holder 13 shown in FIG. 3 is excludedfrom the fixing mechanism 10 shown in FIG. 8. To be more specific, inthe fixing mechanism 10 shown in FIG. 8, the probe card 11 is joined tothe support frame 12 by a plurality of first fastening members 16Aarranged about the axis of the probe card 11 as in the fixing mechanismshown in FIG. 3. The outer circumferential edge of the probe card 11 isdisposed on the inner circumferential edge portion 14A of the head plate14. Also, the outer circumferential edge portion 12A of the supportframe 12 is fastened and fixed to the circumferential edge portion 14Aof the central hole of the head plate 14 by a plurality of secondfastening members 16B, and a clearance 6 serving to absorb the thermalexpansion of the circuit substrate 11C is formed between the outercircumferential surface of the circuit substrate 11C included in theprobe card 11 and the inner circumferential surface of the outercircumferential edge portion 12A of the support frame 12. It followsthat, according to the fixing mechanism shown in FIG. 8, it is possibleto obtain the function and effect similar to those described previouslyin conjunction with the other embodiments of the present invention. Inaddition, since the holder is omitted in the embodiment shown in FIG. 8,it is possible to eliminate the influences given by the thermalexpansion to the holder.

The present invention is not limited to each of the embodimentsdescribed above, and it is possible to modify the present invention invarious fashions within the technical scope of the present invention.For example, in each of the embodiments described above, the probe card11 is reinforced by the support frame 12. However, it is also possibleto apply the technical idea of the present invention to the case wherethe fixing mechanism does not include the support frame 12. Also, ineach of the embodiments described above, the support frame is shapedlike a disk. However, it is also possible for the support frame to beshaped like a disk having an opening formed on the inside thereof like awheel. Also, in each of the embodiments described above, the sum inthickness of the circuit substrate 11C included in the probe card 11 andthe support frame 12 is substantially equal to the thickness of theouter circumferential edge portion 12A of the support frame 12. However,it is possible for the thickness of the outer circumferential edgeportion 12A to be larger than the sum in thickness of the circuitsubstrate 11C and the inside portion of the support frame 12. Further,in each of the embodiments described above, the support frame 12 ispositioned on the upper surface of the probe card 11. However, it ispossible for the support frame 12 to be positioned on the lower surface,the upper surface, or both the lower and upper surfaces of the probecard 11.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the present invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

1. A fixing mechanism arranged within a probe unit for examining theelectrical characteristics of a target object, the target object beingmaintained under a high-temperature environment within a probe chamber,comprising: a probe card provided with a plurality of probes which areto be brought into an electrical and mechanical contact with the targetobject, which is configured to examine the electrical characteristics ofthe target object, the probe card being exposed to a high-temperatureatmosphere; a support frame configured to support the probe card in thecentral portion thereof; a plurality of first fastening membersconfigured to fasten the probe card on the support frame to fix theprobe card; a holding frame configured to hold the probe card and thesupport frame in the outer peripheral portions thereof so as to permitthe probe card to be thermally expanded toward the periphery thereof,the holding frame being fixed to the probe unit; and a plurality ofsecond fastening members configured to fasten the holding frame on thesupport frame to fix the holding frame.
 2. A fixing mechanism accordingto claim 1, wherein the probe card is held between the holding frame andthe support frame.
 3. A fixing mechanism according to claim 1, whereinthe outer circumferential edge portion of the probe card is positionedbetween the support frame and the holding frame, and a clearance isformed on the outside of the outer circumferential surface of the probecard.
 4. A fixing mechanism according to claim 1, wherein each of thesupport frame and the holding frame is formed of a material having a lowthermal expansion coefficient.
 5. A fixing mechanism according to claim1, wherein a heat-insulating material layer is formed on the lowersurface of at least one of the support frame and the holding frame.
 6. Afixing mechanism according to claim 1, further comprising a head platehaving the holding frame fixed thereto.
 7. A fixing mechanism accordingto claim 1, wherein the holding frame corresponds to the head plate. 8.A card holder for fixing a probe card on a probe unit that examines anelectrical characteristic of a target object, the probe card includingprobes for electrically contacting the target object in the probe unit,the card holder comprising: an annular outer portion configured forattachment to the probe unit; and an inner flange portion extending fromthe outer portion; wherein: the inner flange portion comprises anopening and an inner edge defining the opening in which the probe cardcan be located; the inner flange portion comprises a plurality of cutportions, each cut portion extending from the inner edge toward theouter portion; and the cut portions are arranged at regular intervals ina circumferential direction along the inner edge of the opening.
 9. Thecard holder according to claim 8, wherein the inner flange portioncomprises a plurality of slits, each of the slits being provided betweenadjacent cut portions and extending along the cut portions.
 10. A fixingmechanism for fixing a probe card on a probe unit that examines anelectrical characteristic of a target object, the probe card havingprobes for electrically contacting the target object in the probe unit,the fixing mechanism comprising: a fixing portion provided on the probeunit for fixing the probe card to the probe unit; and a card holder forholding the probe card so that the probe card electrically contacts thetarget object, the card holder being configured to be interposed betweenthe probe card and the probe unit and hold the probe card, the cardholder comprising: an annular outer portion fixed to the fixing portion;and an inner flange portion extending from the outer portion; wherein:the inner flange comprises an opening and an inner edge defining theopening in which the probe card can be located; the inner flange portioncomprises a plurality of cut portions, each cut portion extending fromthe inner edge toward the outer portion; and the cut portions arearranged at regular intervals in a circumferential direction along theinner edge of the opening.
 11. The fixing mechanism according to claim10, wherein the inner flange portion comprises a plurality of slits,each of the slits being provided between adjacent cut portions andextending along the cut portions.
 12. The fixing mechanism according toclaim 10, wherein the fixing portion is coupled to the outer portion.13. The fixing mechanism according to claim 10, wherein the fixingportion corresponds to a head plate of the probe unit.